Unbelievable, I have just spend 57 minutes on the chat thing, spoke to three different helpdesks who fobbed me off and finally registered a complaint case for a senior manager to ring me and within minutes you have provided the answer. I can't thank you enough, although I haven't worked fully through the stages I'm sure the answer to my issue lies in that briefing. Once again many thanks for your prompt and helpful response.
Well the Briefing was correct you can't licence a stand alone version when you have a CC membership and without asking for it I had been given free membership which is why I struggled getting the stand alone to work. So I followed the suggestion in the link to install using a different Adobe ID, we used my husbands first checking he had no CC membership. Lo and behold when we started the install using his ID he suddenly gained a CC free membership as well. Back onto the chat with their tech team, yes everything I had found out was correct but the only way to get the programme to act as a stand alone version is to wait for the CC membership to run out in 30 days when it will revert to perpetual (they confirmed I had bought LR6 perpetual when I first started this saga at lunch time Uk time). So it looks as though the stand alone upgrades aren't actually intended to be used stand alone they are intended to try to force people into upgrading to CC.
Don't know if anyone else has done the upgrade but I now have two completely independent versions on my PC it hasn't upgraded in the traditional sense of removing one and replacing it just created a new version.
Will see what happens in 30 days it will probably stop working completely but I'll cross that bridge when I come to it I suppose, on the bright side 5.7 is still working perfectly.
So it looks as though the stand alone upgrades aren't actually intended to be used stand alone they are intended to try to force people into upgrading to CC.
If have performed this procedure, I tried the free trial of Lightroom CC (I did not have a paid subscription), then before the trial expired I purchased LR 6, applied the serial number as instructed, and now I have a working standalone version of LR 6.